<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        body,ul{
            margin: 0;
        }
        ul{
            list-style: none;
            padding: 0;
        }
        a{
            text-decoration: none;
        }
        .nav{
            width: 100%;
            height: 50px;
            background-color: skyblue;
            /* margin-top: 50px; */
        }
        
        .nav >ul{
            width: 1200px;
            /* border: 1px solid #000; */
            margin: 0 auto;
            z-index: 0;
            
        }
        .nav >ul >li{
            float: left;
            height: inherit;
            position: relative;
            font-size: 16px;
            /* border: 1px solid #000; */
            
        }
        .nav >ul >li a{
            padding: 0 20px;
            display: block;
            line-height: 50px;
            color: #000;
        }
        .clearfix::after{
            content: "";
            display: block;
            clear: both;
        }
        .nav >ul >li a:hover{
            background-color: rgb(3, 87, 121);
            color: #fff;
        }
        .nav ul li .submenu{
            position: absolute;
            /* border: 1px solid #000; */
            left: 0;
            right: 0;
            display: none;
            z-index: 3;
        }
        .nav .submenu li a{
            line-height: 40px;
            background-color: skyblue;
        }
        .nav ul li:hover .submenu{
            display: block;
        }

        /* .nav ul li .submenu li a:hover{
            color: #fff;
            background-color: rgb(6, 104, 144);
        } */
         .banner .banner-content{
            width: 100%;
            height: 500px;
            position: relative;
         }
        .banner .banner-content img{
            width: 100%;
            height: 100%;
            object-fit: cover;
            position: absolute;
        }
        .banner .banner-content img.active{
            z-index: 2;
        }
    </style>
</head>
<body>
    <div class="nav">
        <ul class="clearfix">
            <li><a href="#">首页</a></li>
            <li><a href="#">免费直播课</a></li>
            <li>
                <a href="#">web前端工程师</a>
                <ul class="submenu">
                    <li><a href="#">HTML5+CSS3</a></li>
                    <li><a href="#">JAVASCRIPT</a></li>
                    <li><a href="#">VUE3</a></li>
                </ul>
            </li>
            <li><a href="#">Java架构师</a></li>
            <li><a href="#">实战案例视频</a></li>
            <li><a href="#">关于我们</a></li>
        </ul>
    </div>

    <!-- 轮播图 -->
     <div class="banner">
        <div class="banner-content">
            <img src="./assets/1.png" alt="" class="active">
            <img src="./assets/2.png" alt="">
        </div>
     </div>
</body>
</html>